Included Angle of a Triangle

 The included anlgle  mention in two line segement and the line meet at a common point is said to be included angle. In triangle included anlges is divided into three category, they are acute angle triangle, obtuse angle triangle, and right angle triangles In this article we will discuss about included angle of a triangle with suitable example problems.

Included anlge:

included angle

Briefly Describle about Included Angle of a Triangle

 

on the basis of included angle , the  triangle are classified into three types they are shown in the below.

  • Right angle triangle
  • Acute angle triangle
  • Obtuse angle triangle

 

Right angle triangle:

  right angle triangle

    Here the angle 900 is included to Qp and QR. If one of the angle is 900 then it is called right angle triangle the total angles is 1800

 

Acute angle triangle:

 

acute angle triangle 

   Any one of the included angle of a traingle ABC, BAC and ACB is less than 900. Then it is said to be acute angle triangle the total angle is 180o.

Obtuse angle triangle:

  obtuse angle triangle

   Here the  angle is included of a triangle  BA and BC 110o .if any one of the angle is greater than 90o then it is said to be obtuse angle triangle the total angle is 180o.

 

Problems in Included Angle of a Triangle Tutor

 

Identifying the angle of a triangle

Problem (i): If the sum of included angle of right angle triangle  is 180o the angles are 40o and 50o.Find the other angle?

Solution:

If the sum of included angle of right angle triangle  is 180o the angles are 40o and 50o .Find the other angle

Step 1:  Here a+b+c = 180. Here angles are 40o and 50o

Step 2: 50o +40o+c = 180o

90o  +c =  180o

step 3: Subtracting both sides by 90o

90o  +C-90o =  180o -90o

c = 90o

step 4:  The angle is 90o

Problem (ii): If the sum of included angle of acute triangle  is 180o the angles are 60o and 20o. Find the other angle?

Solution:

If the sum of included angle of acute triangle  is 180o the angles are 60o and 20o. Find the other angle

Step 1:  Here a+b+c = 180. Here  the angle are 60o and  20o 

Step 2: 60o +20o+c = 180o

80o  +c =  180o

step 3: Subtracting both sides by 80o

80o  +C-80o =  180o -80o

C = 100o

step 4: The other angle is 100o.